[1] Univ Med Ctr Hamburg, IVDP German Ctr Hlth Serv Dermatol, D-20246 Hamburg, Germany
[2] Hue Coll Med & Pharm, Dept Obstet & Gynecol, Hue City, Vietnam
[3] Univ Med Ctr Essen, Dept Obstet & Gynecol, Essen, Germany
[4] Univ Med Ctr Freiburg, Dept Dermatol, Freiburg, Germany
[5] Univ Med Ctr Freiburg, Dept Obstet & Gynecol, Sect Gynecol Infectiol, Freiburg, Germany